I doubt I'd hit the bug described, but when I do a "clean install" I often create an encrypted sparse disk image onto a network volume and a copy on the Desktop

I doubt I'd hit the bug described, but when I do a "clean install" I often create an encrypted sparse disk image onto a network volume and a copy on the Desktop of my new install. Unrelated, I do my bootable backup as a "smart backup" (only copy changes) to a usb-disk. I can see myself doing that to a sparse image on the network. As I set up my new computer I'll move stuff or delete things out of the sparse disk image from my Desktop, then periodically reclaim space. I only do this every 5+ years or so. I haven't done this with APFS, yet either. But those are a few of my use cases that dd wouldn't cover.